CN115946452A

CN115946452A - Liquid ejecting apparatus, image processing method, and image processing program

Info

Publication number: CN115946452A
Application number: CN202211213593.0A
Authority: CN
Inventors: 碓井雅也
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2021-10-08
Filing date: 2022-09-30
Publication date: 2023-04-11
Also published as: US11886943B2; JP2023056633A; US20230116007A1

Abstract

The invention discloses a liquid ejecting apparatus, an image processing method, and an image processing program. The liquid ejecting apparatus includes: a printing unit for printing an inspection image; a reading unit configured to read the inspection image printed by the printing unit; and an analyzing unit that performs analysis based on a reading result read by the reading unit, the inspection image having a first position detection mark printed in a first color, a second position detection mark printed in the first color, and an inspection pattern of a plurality of colors including a second color inspection pattern printed in a second color different from the first color, the printing unit printing the second color inspection pattern at a position adjacent to the first position detection mark, the analyzing unit specifying a first position of the first position detection mark in a first area and specifying a second position of the second position detection mark in a second area narrower than the first area.

Description

Liquid discharge device, image processing method, and image processing program

Technical Field

The present disclosure relates to a liquid ejection device, an image processing method, and an image processing program.

Background

An image processing method for determining a recording defect using a recorded test pattern is known. The inkjet recording apparatus of patent document 1 prints a non-ejection detection pattern including a detection mark. The detection mark is a mark used for position detection. The inkjet recording apparatus reads the non-ejection detection pattern and performs non-ejection detection processing based on the read result. The inkjet recording apparatus performs the non-ejection detection process to determine the defective ejection nozzle.

Patent document 1: japanese laid-open patent publication No. 2015-3515

The detection accuracy of the detection mark may be lowered by the positional relationship of the image adjacent to the position detection mark used for position detection or by the influence of the color of the image adjacent to the position detection mark.

Disclosure of Invention

The liquid ejecting apparatus of the present disclosure includes: a printing unit for printing an inspection image; a reading unit configured to read the inspection image printed by the printing unit; and an analysis unit configured to perform analysis based on a result of reading by the reading unit, wherein the inspection image includes a first position detection mark printed in a first color, a second position detection mark printed in the first color, and a plurality of color inspection patterns including a second color inspection pattern printed in a second color different from the first color, the printing unit prints the second color inspection pattern at a position adjacent to the first position detection mark, and the analysis unit specifies a first position of the first position detection mark in a first region and specifies a second position of the second position detection mark in a second region narrower than the first region.

According to the image processing method of the present disclosure, an inspection image having the first position detection mark formed with a first color, the second position detection mark formed with the first color, and inspection patterns of a plurality of colors including the second color inspection pattern formed with a second color different from the first color is printed in such a manner that the second color inspection pattern is arranged at a position adjacent to the first position detection mark, the inspection image is read and a read result is acquired, a first position of the first position detection mark is specified in a first area, and a second position of the second position detection mark is specified in a second area narrower than the first area.

According to an image processing program executed by a processor of a liquid ejection device that prints an inspection image of the present disclosure, the following processing is executed: printing the inspection image having the first position detection mark formed in a first color, the second position detection mark formed in the first color, and the inspection pattern of a plurality of colors including the second color inspection pattern formed in a second color different from the first color, in such a manner that the second color inspection pattern is arranged at a position adjacent to the first position detection mark, reading the inspection image and obtaining a read result, specifying a first position of the first position detection mark in a first region, and specifying a second position of the second position detection mark in a second region narrower than the first region.

Drawings

Fig. 1 is a schematic configuration diagram of a printing apparatus.

Fig. 2 is a schematic configuration diagram of the printing apparatus.

Fig. 3 is a diagram showing a relationship between a print medium and a print head.

Fig. 4 is a functional block diagram of the printing apparatus.

Fig. 5 is a diagram showing an outline of a test pattern image.

Fig. 6 is an enlarged view of a test pattern image including a first mark.

Fig. 7 is a graph showing the concentration distribution in the first measurement region.

Fig. 8 is an enlarged view of a test pattern image including a second mark.

Fig. 9 is a graph showing the concentration distribution in the second measurement region.

Fig. 10 is a flowchart showing image processing performed in the printing apparatus.

Fig. 11 is an enlarged view of a test pattern image including a third mark.

Description of the reference numerals

10 8230and a printing device; 11 \ 8230and a delivery shaft; 13 \ 8230, a delivery roller pair; 13A 8230, a first delivery roller; 13B 8230and a second delivery roller; 15 \ 8230and reading sensor; 16 \ 8230and a printing mechanism; 17 \ 8230and a sliding frame; 18 \ 8230a print head; 19 \ 8230and a carriage supporting shaft; 20 \ 8230and ink jet nozzle; 20C 8230, cyan ink nozzle row; 20LC 8230, bright cyan ink nozzle train; 20M 8230; a magenta ink nozzle train; 20LM 8230, bright magenta ink nozzle row; 20Y 8230and yellow ink nozzle row; 20K 8230and black ink nozzle row; 25 8230and conveying roller pair; 25A \ 8230and a first conveying roller; 25B 8230and a second conveying roller; 27\8230anda winding shaft; 30 \ 8230and a control unit; 31 \ 8230and a printing control part; 33 8230and a reading control part; 35 \ 8230and a data processing part; 37 8230j, a storage part; 40 8230a display unit; 50 8230and a communication interface; 60 \ 8230and a conveying mechanism; 70 8230a printing driving mechanism; 80 \ 8230a print head driving mechanism; 90 \ 8230and a detection mechanism; 95 \ 8230and a first side plate; 97' \ 8230and a second side plate; 100 \ 8230and test pattern images; 110, 8230and marking images; 110A 8230, a first mark; 110B 8230and a second mark; 110C 8230and a third mark; 110D 8230and a fourth mark; 110E \8230afifth mark; 110F \8230asixth mark; 110G 8230and the seventh mark; 110H 8230; eighth mark; 120, 8230and pattern image; 120A 8230and a first pattern; 120B 8230and a second pattern; 120C 8230and a third pattern; 120D 8230and a fourth pattern; 120E 8230and the fifth pattern; 120F 8230and the sixth pattern; 122 \ 8230a line image; 130 \ 8230and a measuring area; 130A \ 8230a first measurement area; 130AL 8230a first measurement zone length; 130AW 8230, width of the first measuring area; 130B \ 8230a second measurement area; 130BL \8230asecond measurement region length; 130BW \8230asecond measurement area width; 130C 8230and a third measurement area; 130CL \8230athird measurement zone length; 130CW \ 8230and a third measurement zone width; 160A \8230andthe first marker concentration distribution; 160B \8230anda second marker concentration profile; 170A 8230and the first pattern density distribution; 170F, 8230; sixth pattern concentration distribution; 170AK 8230, a hypothetical first pattern concentration profile; m8230and printing medium; MD 8230and moving direction; p1 \ 8230, the position of the center of gravity of a first mark; P1A \8230, a virtual center of gravity position; p2 \ 8230and the second mark of the gravity center position; PD 8230and the arrangement direction of nozzles; r1 8230, medium roll R2 8230, roll taking; TD 8230and conveying direction; VL1 8230a first imaginary line; VL 2\8230asecond phantom line.

Detailed Description

Fig. 1 and 2 show a schematic configuration of the printing apparatus 10. Fig. 1 is a view of the printing apparatus 10 viewed from the + X direction. Fig. 2 is a view of the printing apparatus 10 viewed from the + Z direction. The printing device 10 prints on the print medium M fed from the medium roll R1. The printing apparatus 10 is of an inkjet type that ejects ink onto the print medium M. The printing apparatus 10 corresponds to an example of a liquid ejecting apparatus. The print medium M corresponds to an example of a medium.

The figures, which comprise a part of fig. 1, show an X, Y, Z coordinate system. The X-axis, the Y-axis and the Z-axis are mutually orthogonal. The X axis is parallel to the installation surface of the printing apparatus 10. The X axis is an axis parallel to the rotation axis of the media roll R1 loaded in the printing device 10. The rotation axis of the media roll R1 is an imaginary rotation center axis when the media roll R1 rotates. The direction from the depth side to the front side in fig. 1 is the + X direction. The direction from the near side toward the depth side in fig. 1 is the-X direction. The Y axis is parallel to the installation surface of the printing apparatus 10. The Y-axis is an axis orthogonal to the rotational axis of the media roll R1. The direction from the right side to the left side of the printing apparatus 10 shown in fig. 1 is the + Y direction. The direction from the left side to the right side of the printing apparatus 10 shown in fig. 1 is the-Y direction. The Z axis is an axis perpendicular to the installation surface of the printing apparatus 10. The direction from the installation surface to the upper side is the + Z direction. The direction from above toward the installation surface is the-Z direction.

Fig. 1 and 2 show the respective portions arranged along the printing medium M. The printing apparatus 10 shown in fig. 1 and 2 includes a feed shaft 11, a feed roller pair 13, a reading sensor 15, a printing mechanism 16, a conveying roller pair 25, and a take-up shaft 27.

The feed shaft 11 supports a medium roll R1 in which the print medium M is wound in a roll shape. The feed shaft 11 is rotatably supported. The delivery shaft 11 may be connected to a not-shown rotation drive mechanism. The rotation driving mechanism rotates the delivery shaft 11. The rotating feed shaft 11 feeds out the printing medium M wound into the medium roll R1.

The delivery roller pair 13 delivers the printing medium M toward the printing mechanism 16. Hereinafter, a direction in which the printing medium M is conveyed at a position facing the printing mechanism 16 is referred to as a conveyance direction TD. The pair of delivery rollers 13 nip the printing medium M. The feed roller pair 13 includes a first feed roller 13A and a second feed roller 13B. The first feed roller 13A is disposed at a position in the + Z direction of the second feed roller 13B. The first delivery roller 13A contacts the surface of the printing medium M on the + Z direction side. The second feed roller 13B contacts the surface of the print medium M on the-Z direction side. The printing medium M is nipped by the first delivery roller 13A and the second delivery roller 13B. One of the first feed roller 13A and the second feed roller 13B is connected to a drive mechanism, not shown. One of the first feed roller 13A and the second feed roller 13B is rotated by a driving force of the driving mechanism. The other of the first delivery roller 13A and the second delivery roller 13B is driven to rotate. The delivery roller pair 13 delivers the printing medium M toward the printing mechanism 16 by the driving force of the driving mechanism. The delivery roller pair 13 then delivers the printing medium M in the direction opposite to the delivery direction TD.

The reading sensor 15 reads the surface of the printing medium M. The reading Sensor 15 is constituted by an Image Sensor such as a CIS (Contact Image Sensor) or a CCD (Charge Coupled Device). The reading sensor 15 shown in fig. 1 reads the entire width of the printing medium M parallel to the X axis. In the printing apparatus 10 shown in fig. 1 and 2, the reading sensor 15 reads the printing medium M positioned between the pair of feed rollers 13 and the printing mechanism 16. The printing apparatus 10 shown in fig. 1 and 2 conveys the printing medium M in a direction opposite to the conveying direction TD. The read sensor 15 reads the printing medium M conveyed in a direction opposite to the conveying direction TD. The reading sensor 15 reads an image such as the test pattern image 100 printed on the printing medium M by the printing mechanism 16. The test pattern image 100 will be described later. The position of the reading sensor 15 is not limited to the position between the delivery roller pair 13 and the printing mechanism 16. The reading sensor 15 may be disposed at a position between the printing mechanism 16 and the conveying roller pair 25 on the conveying path of the printing medium M. The reading sensor 15 corresponds to an example of a reading unit.

The reading sensor 15 includes a light emitting portion and a light receiving portion, which are not shown. The light emitting unit sequentially switches red light, green light, and blue light to emit light. The light receiving unit receives light reflected from the printing medium M when the light emitting unit emits light of each color. The light reception data when the light emitting section emits red light is represented as a red channel. The red channel is image data from which a red component is extracted. The light reception data when the light emitting section emits green light is represented as a green channel. Is image data from which a green component is extracted. The light reception data when the light emitting section emits blue light is represented as a blue channel. The blue channel is image data from which a blue component is extracted. The read data generated by the read sensor 15 is image data including a red channel, a green channel, and a blue channel. Any one of the red, green, and blue channels corresponds to an example of the first and second channels.

The printing mechanism 16 prints an image on the print medium M. The printing mechanism 16 ejects ink onto the printing medium M to form an image. As shown in fig. 1, the printing mechanism 16 includes a carriage 17 and a printing head 18. The printhead 18 has a plurality of ink nozzles 20. The printing mechanism 16 is supported by a carriage support shaft 19 shown in fig. 2. The printing mechanism 16 shown in fig. 1 and 2 moves the carriage 17, but is not limited thereto. The printing mechanism 16 may be a line head type in which the printing head 18 is fixed to the printing medium M at the time of printing. The printing mechanism 16 corresponds to an example of a printing unit. The ink corresponds to an example of the liquid.

The carriage 17 supports a print head 18. The carriage 17 moves in the moving direction MD or in the direction opposite to the moving direction MD along the carriage support shaft 19 shown in fig. 2. The printing mechanism 16 is moved relative to the print medium M by the movement of the carriage 17. The carriage support shaft 19 shown in fig. 2 is parallel to the X axis or substantially parallel thereto. The carriage 17 moves in the + X direction and the-X direction with respect to the print medium M. The printing mechanism 16 scans the ink nozzles 20 with respect to the print medium M by the movement of the carriage 17. As shown in fig. 2, the + X direction corresponds to the moving direction MD and corresponds to an example of the first direction. The moving direction MD may also be the-X direction. The carriage 17 is moved by a driving force of a carriage driving mechanism, not shown. The carriage 17 corresponds to an example of the ejection section driving mechanism. In the printing apparatus 10 shown in fig. 1 and 2, the printing mechanism 16 moves relative to the print medium M, but is not limited thereto. The printing mechanism 16 moves relative to the print medium M.

The print head 18 is supported by the carriage 17. The print head 18 has a plurality of ink nozzles 20 on a printing surface facing the print medium M. The ink nozzles 20 are capable of ejecting ink toward the print medium M. The ink nozzle 20 corresponds to an example of a nozzle. The structure of the ink nozzle 20 will be described later. The print head 18 is supplied with inks of a plurality of colors from ink tanks or ink cartridges, not shown.

The carriage support shaft 19 movably supports the carriage 17. The carriage support shaft 19 is supported by the first side plate 95 and the second side plate 97 as shown in fig. 2. The first side plate 95 is disposed at a position in the-X direction of the conveyed printing medium M. The second side plate 97 is disposed at a position in the + X direction of the print medium M being conveyed. The carriage support shaft 19 is supported along a shaft intersecting the Y axis. The carriage support shaft 19 shown in fig. 2 is supported parallel or substantially parallel to the X axis. The first side plate 95 and the second side plate 97 can also support the pair of feed rollers 13, the reading sensor 15, and the pair of conveying rollers 25.

The transport roller pair 25 transports the print medium M printed by the printing mechanism 16. The conveying roller pair 25 nips the printing medium M. The conveying roller pair 25 has a first conveying roller 25A and a second conveying roller 25B. The first conveyance roller 25A is disposed at a position in the + Z direction of the second conveyance roller 25B. The first transport roller 25A contacts the surface of the print medium M on the + Z direction side. The second transport roller 25B contacts the surface of the print medium M on the-Z direction side. The printing medium M is nipped by the first conveyance roller 25A and the second conveyance roller 25B. One of the first conveying roller 25A and the second conveying roller 25B may be connected to a driving mechanism not shown. When one of the first conveying roller 25A and the second conveying roller 25B is connected to the driving mechanism, it is rotated by the driving force of the driving mechanism. The other of the first conveying roller 25A and the second conveying roller 25B is driven to rotate. The transport roller pair 25 guides the print medium M to the winding roll R2. The conveying roller pair 25 may convey the printing medium M in a direction opposite to the conveying direction TD.

The winding shaft 27 winds the printing medium M printed by the printing mechanism 16 into a winding roll R2. The take-up shaft 27 supports the take-up roll R2. The take-up shaft 27 is rotatably supported. The winding shaft 27 may be connected to a not-shown rotation driving mechanism. The rotation driving mechanism rotates the take-up shaft 27. The rotating take-up shaft 27 winds the print medium M into a take-up roll R2. The winding shaft 27 may wind the printing medium M around a winding core not shown.

The printing device 10 shown in fig. 1 and 2 uses the printing medium M wound into the medium roll R1, but is not limited thereto. The printing apparatus 10 may use cut paper cut into a predetermined size. When the printing apparatus 10 uses cut paper, the feeding shaft 11 and the winding shaft 27 are changed to the paper feed cassette and the paper discharge tray, respectively.

Fig. 3 shows the relationship between the print medium M and the print head 18. Fig. 3 omits the carriage 17 and the carriage support shaft 19. Fig. 3 shows a read sensor 15. The print head 18 shown in fig. 3 moves in the moving direction MD to print an image on the print medium M. The moving direction MD shown in fig. 3 corresponds to the + X direction. The plurality of ink nozzles 20 are disposed on a printing surface of the print head 18 facing the print medium M. The plurality of ink nozzles 20 form a plurality of nozzle columns. The ink nozzles 20 shown in fig. 3 form a magenta ink nozzle row 20M, a bright magenta ink nozzle row 20LM, a cyan ink nozzle row 20C, a bright cyan ink nozzle row 20LC, a yellow ink nozzle row 20Y, and a black ink nozzle row 20K.

The magenta ink nozzle row 20M has a plurality of ink nozzles 20 arrayed along the nozzle array direction PD. The nozzle arrangement direction PD shown in fig. 3 is the same direction as the transport direction TD, but is not limited thereto. The nozzle arrangement direction PD is a direction different from the moving direction MD. The ink nozzle 20 contained in the magenta ink nozzle train 20M can eject magenta ink. Magenta ink refers to magenta ink. Magenta ink is supplied to the print head 18 from an ink tank or ink cartridge, not shown. The magenta ink supplied to the print head 18 is ejected at the ink nozzles 20 included in the magenta ink nozzle row 20M.

The light magenta ink nozzle row 20LM has a plurality of ink nozzles 20 arrayed along the nozzle array direction PD. The ink nozzles 20 contained in the light magenta ink nozzle row 20LM are capable of ejecting light magenta ink. The light magenta ink refers to light magenta ink. The magenta ink is supplied to the print head 18 from an ink tank or ink cartridge, not shown. The light magenta ink supplied to the print head 18 is ejected at the ink nozzles 20 included in the light magenta ink nozzle row 20 LM.

The cyan ink nozzle train 20C has a plurality of ink nozzles 20 arrayed along the nozzle array direction PD shown in fig. 3. The ink nozzles 20 contained in the cyan ink nozzle train 20C can eject cyan ink. Cyan ink refers to ink of cyan. Cyan ink is supplied to the print head 18 from an ink tank or ink cartridge, not shown. The cyan ink supplied to the print head 18 is ejected at the ink nozzles 20 included in the cyan ink nozzle train 20C.

The bright cyan ink nozzle row 20LC has a plurality of ink nozzles 20 aligned along the nozzle alignment direction PD. The ink nozzles 20 contained in the bright cyan ink nozzle train 20LC can eject bright cyan ink. A light cyan ink is an ink of light cyan. Bright cyan ink is supplied to the print head 18 from an ink tank or ink cartridge, not shown. The light cyan ink supplied to the print head 18 is ejected at the ink nozzles 20 included in the light cyan ink nozzle train 20 LC.

The yellow ink nozzle row 20Y has a plurality of ink nozzles 20 arrayed along the nozzle array direction PD. The ink nozzles 20 included in the yellow ink nozzle row 20Y can eject yellow ink. Yellow ink refers to yellow ink. Yellow ink is supplied to the print head 18 from an ink tank or ink cartridge, not shown. The yellow ink supplied to the print head 18 is ejected from the ink nozzles 20 included in the yellow ink nozzle row 20Y.

The black ink nozzle row 20K has a plurality of ink nozzles 20 arranged along the nozzle arrangement direction PD. The ink nozzles 20 included in the black ink nozzle row 20K can eject black ink. The black ink refers to black ink. Black ink is supplied to the print head 18 from an ink tank or an ink cartridge, not shown. The black ink supplied to the print head 18 is ejected from the ink nozzles 20 included in the black ink nozzle row 20K.

The print head 18 shown in fig. 3 can eject six kinds of inks, but is not limited thereto. The print head 18 may be configured to be able to eject five or less types of ink, or may be configured to be able to eject seven or more types of ink. The print head 18 may be capable of ejecting two or more types of ink. The number of the ink nozzles 20 included in each nozzle row shown in fig. 3 is 14, but is not limited thereto. The number of the ink nozzles 20 included in each nozzle row may be less than 14 or more than 14. The number of ink nozzles 20 included in each nozzle row can be set as appropriate. The print head 18 shown in fig. 3 is arranged in the order of a magenta ink nozzle row 20M, a bright magenta ink nozzle row 20LM, a cyan ink nozzle row 20C, a bright cyan ink nozzle row 20LC, a yellow ink nozzle row 20Y, and a black ink nozzle row 20K with respect to the moving direction MD, but is not limited thereto. The arrangement order of the nozzle rows can be changed as appropriate.

Magenta, light magenta, cyan, light cyan, yellow, and black are examples of the ink colors, and are not limited thereto. Any two colors of magenta, light magenta, cyan, light cyan, yellow, and black correspond to an example of the first color and the second color.

Fig. 4 shows a block diagram configuration of the printing apparatus 10. The printing apparatus 10 includes a control unit 30, a display unit 40, a communication interface 50, a conveyance mechanism 60, a print drive mechanism 70, a print head drive mechanism 80, and a detection mechanism 90. FIG. 4 represents the interface as an I/F.

The control unit 30 is a controller that controls each part of the printing apparatus 10. The control Unit 30 includes a control processor such as a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The control unit 30 operates as a functional portion by executing a program in a control processor. The RAM and the ROM function as work areas. The control unit 30 corresponds to an example of a processor.

The control unit 30 includes a storage unit 37. The storage unit 37 stores various programs such as a print control program that operates in the control unit 30, and various data. The storage unit 37 stores test pattern data, calibration data, and the like, which will be described later, as data. The RAM and the ROM may operate as the storage unit 37, and may include a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor memory, and the like.

The control unit 30 functions as a print control unit 31, a read control unit 33, and a data processing unit 35 by executing a print control program. The print control section 31, the read control section 33, and the data processing section 35 are functional sections.

The print control unit 31 controls the print driving mechanism 70 and the print head driving mechanism 80. The print control unit 31 can control the printing mechanism 16 by controlling the print driving mechanism 70 and the print head driving mechanism 80. The print control unit 31 prints an image on the print medium M by the printing mechanism 16. The print control unit 31 acquires print data. The print data is stored in the storage unit 37. Alternatively, the print data is acquired from an external device via the communication interface 50. The print control unit 31 controls the print driving mechanism 70 and the print head driving mechanism 80 based on the print data, thereby printing an image on the print medium M.

The reading control unit 33 controls various sensors such as the reading sensor 15 included in the detection mechanism 90. The reading control unit 33 controls the reading sensor 15 to read the image printed on the printing medium M. The read image is a test pattern image 100 or the like. The read control unit 33 receives the read data read by the read sensor 15 from the read sensor 15. The received read data is sent to the data processing section 35.

The data processing unit 35 analyzes various data based on the data generated by the detection means 90. The data processing unit 35 receives the read data read by the read sensor 15 and analyzes the read data. When the received read data is read data obtained by reading the test pattern image 100, the data processing unit 35 analyzes the read data to specify the image position in the test pattern image 100, generate correction data, determine a defective nozzle, and the like. The data processing unit 35 corresponds to an example of the analysis unit. The read data corresponds to an example of the read result.

The display unit 40 performs various displays according to the control of the control unit 30. The display unit 40 includes a display. The display is constituted by a liquid crystal display, an organic EL (Electro-luminescence), or the like. The display may also have touch input functionality. The display unit 40 displays a setting screen for performing various settings such as printing conditions, an instruction screen for instructing printing, and the like.

The communication interface 50 is communicatively connected to an external device not shown. The communication interface 50 is connected to an external device by wire or wirelessly according to a predetermined communication protocol. The communication interface 50 receives print data, print setting conditions, programs, and the like from an external device. The communication interface 50 transmits the printing result, the maintenance data, and the like of the printing apparatus 10 to the external apparatus.

The transport mechanism 60 transports the printing medium M in the transport direction TD or the direction opposite to the transport direction TD. The transport mechanism 60 includes a feed shaft 11, a feed roller pair 13, a transport roller pair 25, and a take-up shaft 27. The transport mechanism 60 transports the print medium M under the control of the print control unit 31 or the read control unit 33. When the printing apparatus 10 performs printing on the printing medium M, the transport mechanism 60 transports the printing medium M in the transport direction TD under the control of the printing control unit 31. When the reading sensor 15 reads the test pattern image 100 printed on the print medium M, the transport mechanism 60 transports the print medium M in the direction opposite to the transport direction TD under the control of the reading control section 33.

The print driving mechanism 70 drives the printing mechanism 16. The print drive mechanism 70 includes the carriage 17, the carriage drive mechanism, and the carriage support shaft 19. The print driving mechanism 70 moves the carriage 17 in the moving direction MD. By the carriage 17 moving in the moving direction MD, the plurality of ink nozzles 20 included in the print head 18 scan the print medium M. The printing mechanism 16 scans the plurality of ink nozzles 20 by the carriage 17. The scanned ink nozzles 20 eject ink, thereby forming an image on the printing medium M. When the printing mechanism 16 is a line head type, the printing drive mechanism 70 may operate as a correction mechanism for correcting meandering of the printing medium M.

The print head drive mechanism 80 controls the ejection of ink from the ink nozzles 20 under the control of the print control unit 31. The print head driving mechanism 80 includes a driving element such as a piezoelectric element disposed in the print head 18. The ink nozzles 20 are driven by the print head driving mechanism 80 to discharge ink. The print head drive mechanism 80 drives the plurality of ink nozzles 20 to print on the print medium M. The print head driving mechanism 80 prints the test pattern image 100 on the print medium M by driving the plurality of ink nozzles 20.

The detection mechanism 90 detects various operations of the printing apparatus 10, the presence or absence of the printing medium M, and the like. The detection mechanism 90 includes a reading sensor 15, a paper detection sensor not shown, an ink remaining amount sensor, and the like. The detection mechanism 90 is driven under the control of the control unit 30. The reading sensor 15 reads the image printed on the print medium M in accordance with an instruction from the reading control section 33 in the control unit 30. The reading action of the reading sensor 15 corresponds to the detection action. The detection mechanism 90 transmits detection data generated in various sensors to the control unit 30. The reading sensor 15 sends the read data to the control unit 30.

Fig. 5 shows an outline of the test pattern image 100 printed on the print medium M. The test pattern image 100 shown in fig. 5 is printed when the ink ejection nozzle 20 is inspected for a defective ejection. The test pattern image 100 shown in fig. 5 corresponds to an example of the inspection image. The test pattern image 100 of fig. 5 is a part of the image omitted and schematically shown.

The test pattern image 100 is printed based on the test pattern data stored in the storage unit 37. The test pattern data is print data stored in the storage unit 37 in advance. The test pattern data includes information such as the shape and size of each image included in the printed test pattern image 100, and the relative position between each image. The test pattern data may also include color data for each image. The printing apparatus 10 reads the test pattern data stored in the storage unit 37. The printing apparatus 10 prints the test pattern image 100 on the print medium M based on the read test pattern data.

The test pattern image 100 includes a marker image 110 and a pattern image 120. The marker image 110 shown in fig. 5 is composed of a plurality of circular images having a predetermined size. The label image 110 is used when the printing device 10 determines the print position on the print medium M. The pattern image 120 is a pattern composed of a plurality of line images 122. The plurality of line images 122 are configured in a staircase shape. The plurality of line images 122 are printed on one ink nozzle 20. The pattern image 120 is used when the printing apparatus 10 determines a discharge failure of the ink nozzle 20. The pattern image 120 corresponds to an example of the inspection pattern.

The marker image 110 shown in fig. 5 is composed of a first marker 110A, a second marker 110B, a third marker 110C, a fourth marker 110D, a fifth marker 110E, a sixth marker 110F, a seventh marker 110G, and an eighth marker 110H. The first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G are arranged in a direction parallel to the Y axis at positions in the-X direction of the pattern image 120. The second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H are arranged in the direction parallel to the Y axis at positions in the + X direction of the pattern image 120. A plurality of circular images constituting the marker image 110 shown in fig. 5 are printed at positions sandwiching the pattern image 120 in a direction along the X axis. The position of each circle image and the number of each circle image can be changed as appropriate.

The marker image 110 shown in fig. 5 is composed of 8 markers as a circle image, but is not limited thereto. The number of the markers constituting the marker image 110 may be different from 8 markers as long as two or more markers are present. Each of the marks shown in fig. 5 is the same circular shape, but is not limited thereto. The shapes of the plurality of marks may be the same or different as long as the print position of each image printed on the print medium M can be specified. Preferably, the plurality of marks are identical in shape. When the shapes of the plurality of marks are the same, the print positions of the images printed on the print medium M by the respective marks can be easily determined.

The marker image 110 shown in fig. 5 is printed by the black ink nozzle row 20K. The color of the marker image 110 shown in fig. 5 is black. The color of the marker image 110 is not limited to black. The color of the marker image 110 can be set as appropriate.

The pattern image 120 shown in fig. 5 includes a first pattern 120A, a second pattern 120B, a third pattern 120C, a fourth pattern 120D, a fifth pattern 120E, and a sixth pattern 120F. The first pattern 120A, the second pattern 120B, the third pattern 120C, the fourth pattern 120D, the fifth pattern 120E, and the sixth pattern 120F are sequentially printed along the + X direction. The first pattern 120A is printed at a position adjacent to the first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G in the + X direction. In the test pattern image 100, the first pattern 120A is arranged at a position in the + X direction adjacent to the first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G. The sixth pattern 120F is printed at a position adjacent to the second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H in the-X direction. In the test pattern image 100, the sixth pattern 120F is arranged at a position in the-X direction adjacent to the second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H.

The first pattern 120A, the second pattern 120B, the third pattern 120C, the fourth pattern 120D, the fifth pattern 120E, and the sixth pattern 120F are printed by different nozzle rows. The first pattern 120A shown in fig. 5 is printed by the magenta ink nozzle train 20M. The first pattern 120A is a magenta pattern. The second pattern 120B shown in fig. 5 is printed by the light magenta ink nozzle row 20 LM. The second pattern 120B is a pattern of light magenta. The third pattern 120C shown in fig. 5 is printed by the cyan ink nozzle train 20C. The third pattern 120C is a cyan pattern. The fourth pattern 120D shown in fig. 5 is printed by the light cyan ink nozzle train 20 LC. The fourth pattern 120D is a pattern of light cyan. A fifth pattern 120E shown in fig. 5 is printed by the yellow ink nozzle row 20Y. The fifth pattern 120E is a yellow pattern. The sixth pattern 120F shown in fig. 5 is printed by the black ink nozzle row 20K. The sixth pattern 120F is a pattern of black. The pattern image 120 is printed by all the nozzle rows. Each pattern is printed by all the ink nozzles 20 included in each nozzle row.

The first pattern 120A, the second pattern 120B, the third pattern 120C, the fourth pattern 120D, the fifth pattern 120E, and the sixth pattern 120F may be printed in a color different from the above-described color. The color of each pattern can be set as appropriate.

Fig. 6 is an enlarged view of the test pattern image 100 including the first mark 110A. Fig. 6 shows a first mark 110A and a first pattern 120A adjacent to the first mark 110A. The first mark 110A corresponds to an example of the first position detection mark. Fig. 6 also shows a first measurement region 130A. The first measurement region 130A is one of the plurality of measurement regions 130. The measurement region 130 indicates a range to be measured when the data processing unit 35 specifies the positions of the respective marks included in the test pattern image 100. The color of the first mark 110A shown in fig. 6 is black. Black corresponds to an example of the first color. The first pattern 120A shown in fig. 6 is composed of a plurality of line images 122. The color of the first pattern 120A shown in fig. 6 is magenta. Magenta corresponds to an example of the second color. The first pattern 120A corresponds to an example of the second color check pattern.

The data processing section 35 specifies the position of each mark in the read data read by the read sensor 15. The data processing unit 35 determines a concentration distribution in the measurement region 130 by using a range of a predetermined size in the read data as the measurement region 130. The print start position of the test pattern image 100 is controlled by the print control section 31. The reading start position based on the reading sensor 15 is controlled by the reading control section 33. On the other hand, the printing medium M may not be conveyed to the predetermined position due to meandering, slippage of the delivery roller pair 13, or the like. The data processing unit 35 determines the position of each mark by obtaining, for example, a concentration distribution in the measurement region 130 having a predetermined size.

The first measurement region 130A shown in fig. 6 indicates a range for measuring the concentration distribution of the first marker 110A. The first measurement region 130A is a region having a first measurement region width 130AW in a direction parallel to the X axis and a first measurement region length 130AL in a direction parallel to the Y axis. The first measurement region 130A corresponds to an example of the first region.

Fig. 7 shows a concentration distribution in the first measurement region 130A. Fig. 7 shows the concentration distribution on the first virtual line VL1 shown in fig. 6. The first imaginary line VL1 is an imaginary line parallel to the X axis. The data processing unit 35 measures the density distribution in the first measurement region 130A including the density distribution on the first virtual line VL 1. Fig. 7 shows a first mark density distribution 160A corresponding to the first mark 110A and a first pattern density distribution 170A corresponding to the first pattern 120A.

For example, the data processing unit 35 determines the position of the first marker 110A by obtaining the center of gravity of the concentration in the first measurement region 130A. The position of the first mark 110A corresponds to an example of the first position detection mark. As shown in fig. 6, the first measurement region 130A includes a first pattern 120A. As shown in fig. 7, the first pattern density distribution 170A is included in the first measurement area width 130 AW.

Fig. 7 shows a hypothetical first pattern concentration profile 170AK. The virtual first pattern density distribution 170AK is an output value when the first pattern 120A is printed with the black ink nozzle row 20K. The color of the first pattern 120A is black. When the color of the first pattern 120A is black, the density centroid position of the first measurement region 130A becomes a virtual centroid position P1A as shown in fig. 7.

The color of the first pattern 120A is magenta, so the first pattern density distribution 170A is smaller than the virtual first pattern density distribution 170AK. As shown in fig. 7, the density barycentric position of the first measurement region 130A is the first mark barycentric position P1. The first mark center of gravity position P1 corresponds to a first position of the first position detection mark. The color of the first mark 110A is different from the color of the first pattern 120A adjacent to the first mark 110A. With respect to the first mark center of gravity position P1, since the influence of the first pattern density distribution 170A is small, the data processing section 35 can more accurately specify the position of the first mark 110A. In addition, since the data processing unit 35 has a small influence of the first pattern density distribution 170A, the first measurement region 130A can be set to be wide. When the first measurement region 130A is widened, the data processing unit 35 can reliably specify the position of the first mark 110A.

The data processing section 35 analyzes the density distribution of the first mark 110A using the red channel contained in the read data. Since the red channel is light receiving data when the light emitting unit emits red light, the magenta first pattern 120A reflects a large amount of red light, and the black first mark 110A absorbs light. Therefore, when the data processing unit 35 estimates the density distribution from the reflected light printed on the white printing medium M, for example, the output value of the density distribution of the black first marks 110A is increased. That is, since the reflected light of the white printing medium M that reflects red light on one side is mixed with the reflected light of the first pattern a for magenta, the output value of the density distribution of the first pattern a decreases. That is, the data processing unit 35 performs analysis using the red channel, and the output value of the first pattern density distribution 170A is further reduced. Red corresponds to an example of a color related to magenta. The data processing section 35 can suppress the influence of the magenta first pattern 120A adjacent to the first mark 110A. The red channel corresponds to an example of a first channel that extracts a color related to the first color. In addition, although the white printing medium M is shown as an example for easy clarity, according to the above-described concept, the reading sensor 15 may read in a color channel in which the gap between the reflected light of the first mark 110A and the reflected light of the first pattern 120A is large, and thus the color of the printing medium is not limited to white.

The data processing unit 35 uses a green channel from which a green component is extracted when analyzing the first magenta pattern 120A. By using the green channel, the data processing unit 35 can perform analysis with high accuracy while suppressing the influence of the second pattern 120B adjacent to the first pattern 120A and the like. Green corresponds to an example of a color different from the color associated with the second color. The green color channel corresponds to an example of a second channel that extracts a color different from a color related to the second color.

The read data has a red channel that extracts red. Preferably, the data processing section 35 analyzes the first marker 110A using a red color channel. Also, the read data has a green channel extracting a green color different from the red color. Preferably, the data processing section 35 analyzes the first pattern 120A of magenta using the green channel.

The printing apparatus 10 can reduce the influence of the color of the first pattern 120A when determining the position of the first mark 110A.

The color of the first mark 110A is not limited to black. The color of the first pattern 120A is not limited to magenta. For example, the color of the first indicia 110A may also be printed in magenta. The first pattern 120A may also be printed in cyan. The data processing section 35 analyzes the first mark 110A using the green channel and the first pattern 120A using the red channel. Preferably, the data processing unit 35 selects a red channel, a green channel, and a blue channel as appropriate for analysis according to the color of the marker or pattern to be analyzed.

When the data processing unit 35 performs analysis using the red channel, the green channel, and the blue channel, the color of each pattern included in the test pattern image 100 is preferably adjusted in advance. For example, in the case where the first patterns 120A are magenta, it is preferable that the second patterns 120B are cyan. Cyan corresponds to an example of the third color. It is preferable that the color of the second pattern 120B adjacent to the first pattern 120A is a color close to the complementary color of the first pattern 120A. The setter of the test pattern image 100 sets in advance the color of the second pattern 120B adjacent to the first pattern 120A to a color close to the complementary color. The data processing unit 35 uses the green channel when analyzing the first pattern 120A, thereby enabling analysis in which the influence of the cyan second pattern 120B is suppressed.

Fig. 6 and 7 show the first marker concentration distribution 160A obtained in the first measurement region 130A, but the present invention is not limited thereto. Any one of the second mark 110B, the third mark 110C, the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H is measured for the density distribution in the first measurement region 130A.

Fig. 8 is an enlarged view of the test pattern image 100 including the second mark 110B. Fig. 8 shows a second mark 110B and a sixth pattern 120F adjacent to the second mark 110B. The second mark 110B corresponds to an example of the second position detection mark. Fig. 8 also shows a second measurement region 130B. The second measurement region 130B is one of the plurality of measurement regions 130. The color of the second mark 110B shown in fig. 8 is black. The sixth pattern 120F shown in fig. 8 is composed of a plurality of line images 122. The color of the sixth pattern 120F shown in fig. 8 is black.

The second measurement region 130B shown in fig. 8 indicates a range in which the concentration distribution of the second marker 110B is measured. The second measurement region 130B is a region having a second measurement region width 130BW in a direction parallel to the X axis and a second measurement region length 130BL in a direction parallel to the Y axis. The second measurement region 130B corresponds to an example of the second region.

The second measurement region 130B is narrower than the first measurement region 130A. The second measurement area width 130BW shown in fig. 8 is shorter than the first measurement area width 130 AW. Second measurement region length 130BL shown in fig. 8 is shorter than first measurement region length 130 AL. The area of the second measurement region 130B is smaller than the area of the first measurement region 130A.

The storage unit 37 stores test pattern data in advance. The test pattern data includes information on the relative positions of each mark and each pattern. The data processing unit 35 can estimate the position of the second marker 110B with high accuracy by specifying the position of the first marker 110A. The data processing unit 35 can specify the position of the second mark 110B in the second measurement region 130B that is narrower than the first measurement region 130A. The position of the second mark 110B corresponds to an example of the second position detection mark.

Fig. 9 shows a concentration distribution in the second measurement region 130B. Fig. 9 shows the concentration distribution on the second virtual line VL2 shown in fig. 8. The second imaginary line VL2 is an imaginary line parallel to the X axis. The data processing unit 35 measures the density distribution in the second measurement region 130B including the density distribution on the second virtual line VL 2. Fig. 9 shows a second mark density distribution 160B corresponding to the second mark 110B and a sixth pattern density distribution 170F corresponding to the sixth pattern 120F.

For example, the data processing unit 35 determines the position of the second marker 110B by obtaining the center of gravity of the concentration in the second measurement region 130B. As shown in fig. 8, the sixth pattern 120F is not included in the second measurement region 130B. As shown in fig. 9, the sixth pattern density distribution 170F is not included in the second measurement area width 130 BW. The data processing unit 35 can accurately specify the second mark barycentric position P2.

Since the second measurement region 130B is narrower than the first measurement region 130A, the data processing unit 35 is less likely to be affected by the sixth pattern 120F adjacent to the second mark 110B. Also, the setter of the test pattern image 100 can set the color of the sixth pattern 120F adjacent to the second mark 110B to black.

Fig. 8 and 9 show the second marker concentration distribution 160B obtained in the second measurement region 130B, but the present invention is not limited thereto. When the position of the first mark 110A is specified in the first measurement region 130A, the position of the third mark 110C, the position of the fourth mark 110D, the position of the fifth mark 110E, the position of the sixth mark 110F, the position of the seventh mark 110G, and the position of the eighth mark 110H may be specified in a measurement region 130 having the same size as the second measurement region 130B.

As described above, the printing apparatus 10 includes: a printing mechanism 16 that prints a test pattern image 100; a reading sensor 15 for reading the test pattern image 100 printed by the printing mechanism 16; the data processing unit 35 analyzes the read data read by the read sensor 15. The test pattern image 100 has a first mark 110A printed in black, a second mark 110B printed in black, and a pattern image 120 of a plurality of colors including a first pattern 120A printed in magenta different from black. The printing mechanism 16 prints the first pattern 120A at a position adjacent to the first mark 110A. The data processing unit 35 specifies the position of the first marker 110A in the first measurement region 130A. The data processing unit 35 specifies the position of the second mark 110B in the second measurement region 130B that is narrower than the first measurement region 130A.

The printing apparatus 10 can reduce the influence of the first pattern 120A when determining the position of the first mark 110A. Further, the printing apparatus 10 can reduce the influence of the sixth pattern 120F when the position of the second mark 110B is specified. The printing apparatus 10 can accurately specify the position of the first mark 110A and the position of the second mark 110B.

Fig. 6 and 8 show circular images of a predetermined size as the first mark 110A and the second mark 110B. The shapes of the first mark 110A and the second mark 110B are not limited to the circular image. The shape of the first mark 110A and the second mark 110B may be a predetermined shape such as a dragonfly that crosses two lines, for example. The data processing unit 35 estimates the shape of the mark from the output value of the read data. The data processing unit 35 may specify the position of the marker from the estimated shape of the marker.

Preferably, the data processing unit 35 determines the positions of the first mark 110A and the second mark 110B by obtaining the density distribution of the marks. The data processing unit 35 can easily specify the positions of the first mark 110A and the second mark 110B. The data processing unit 35 obtains the position of the marker from the density distribution of the marker, and the setter of the test pattern image 100 can use the circle image as the marker image 110. When the marker image 110 is tilted at the time of printing, the data processing section 35 is less likely to be affected by the tilt.

The data processing unit 35 of the printing apparatus 10 specifies the position of the first mark 110A from the black density distribution in the first measurement region 130A, and specifies the position of the second mark 110B from the black density distribution in the second measurement region 130B.

Since the printing apparatus 10 determines the position of the first mark 110A and the position of the second mark 110B from the density distribution, the positions can be determined with high accuracy.

The test pattern image 100 shown in fig. 5 is printed in the order of the first mark 110A, the first pattern 120A, the second pattern 120B, the third pattern 120C, the fourth pattern 120D, the fifth pattern 120E, the sixth pattern 120F, and the second mark 110B in the direction parallel to the X axis. The first mark 110A and the second mark 110B are printed in parallel to the X axis with the pattern image 120 interposed therebetween. By positioning the first mark 110A and the second mark 110B at positions sandwiching the pattern image 120, the accuracy of determining the position of each image forming the pattern image 120 improves.

The printing mechanism 16 of the printing apparatus 10 prints the pattern image 120 between the first mark 110A and the second mark 110B with respect to the direction parallel to the X axis.

Fig. 10 is a flowchart of image processing performed by the printing apparatus 10. The image processing method shown in fig. 10 is performed by executing a print control program by the control unit 30. The print control program corresponds to an example of the image processing program.

The printing apparatus 10 prints the test pattern image 100 in step S101. The printing apparatus 10 prints the test pattern image 100 based on the test pattern data stored in the storage unit 37. As shown in fig. 5, the test pattern image 100 includes a first mark 110A, a second mark 110B, and a pattern image 120. The first mark 110A is printed by the black ink nozzle row 20K. The first mark 110A is black. The second mark 110B is printed by the black ink nozzle row 20K. The second mark 110B is black.

The test pattern image 100 has a third mark 110C, a fourth mark 110D, a fifth mark 110E, a sixth mark 110F, a seventh mark 110G, and an eighth mark 110H. The third mark 110C, the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H are printed by the black ink nozzle row 20K. The third mark 110C, the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H are black.

The pattern image 120 includes a first pattern 120A, a second pattern 120B, a third pattern 120C, a fourth pattern 120D, a fifth pattern 120E, and a sixth pattern 120F. The first pattern 120A is printed by the magenta ink nozzle train 20M. The first pattern 120A is a magenta pattern. The second pattern 120B is printed by the bright magenta ink nozzle train 20 LM. The second pattern 120B is a pattern of light magenta. The third pattern 120C is printed by the cyan ink nozzle train 20C. The third pattern 120C is a cyan pattern. The fourth pattern 120D is printed by the light cyan ink nozzle train 20 LC. The fourth pattern 120D is a pattern of light cyan. The fifth pattern 120E is printed by the yellow ink nozzle row 20Y. The fifth pattern 120E is a yellow pattern. The sixth pattern 120F is printed by the black ink nozzle row 20K. The sixth pattern 120F is a black pattern.

The first pattern 120A is disposed at a position adjacent to the first mark 110A, the third mark 110C, the fifth mark 110E, and the seventh mark 110G. The sixth pattern 120F is disposed at a position adjacent to the second mark 110B, the fourth mark 110D, the sixth mark 110F, and the eighth mark 110H.

After printing the test pattern image 100, the printing apparatus 10 reads the test pattern image 100 by the reading sensor 15 in step S103. The reading sensor 15 reads the test pattern image 100 and generates read data. The read data includes a red channel, a green channel, and a blue channel. The data processing unit 35 acquires read data generated by the read sensor 15.

After acquiring the read data, the printing apparatus 10 determines the position of the first mark 110A in step S105. The position of the first mark 110A is a print position on the print medium M. The data processing unit 35 estimates the position of the first mark 110A from the print control data used by the print control unit 31. The print control data is control data generated from test pattern data as print data. The data processing unit 35 measures the density distribution of black in the first measurement region 130A including the estimated position. The first measurement region 130A is a region having a first measurement region width 130AW and a first measurement region length 130AL as shown in fig. 6. The data processing unit 35 calculates a density centroid of the black density distribution. The data processing unit 35 determines the position of the first marker 110A by calculating the density center of gravity.

After the printing apparatus 10 determines the position of the first mark 110A, the printing apparatus determines the position of the second mark 110B in step S107. The position of the second mark 110B is a print position on the print medium M. The data processing unit 35 estimates the position of the second marker 110B from the specified position of the first marker 110A. The data processing unit 35 measures the density distribution of black in the second measurement region 130B including the estimated position. The second measurement region 130B is a region having a second measurement region width 130BW and a second measurement region length 130BL as shown in fig. 8. The second measurement region 130B is narrower than the first measurement region 130A. The position of the second marker 110B is estimated based on the determined position of the first marker 110A, so the estimated position of the second marker 110B is estimated with a higher degree of accuracy. Even when the second measurement region 130B is narrower than the first measurement region 130A, the data processing unit 35 can specify the position of the second marker 110B. The data processing unit 35 calculates the density centroid of the black density distribution. The data processing unit 35 determines the position of the second marker 110B by calculating the density center of gravity.

The position of the first mark 110A is determined based on the density distribution of black in the first measurement region 130A, and the position of the second mark 110B is determined based on the density distribution of black in the second measurement region 130B.

The printing apparatus 10 can accurately determine the positions by determining the positions of the first mark 110A and the second mark 110B from the density distribution.

Printing device 10 may also determine the location of third indicia 110C. Fig. 11 is an enlarged view of the test pattern image 100 including the third mark 110C. Fig. 11 shows a third mark 110C and a first pattern 120A adjacent to the third mark 110C. The first pattern 120A is constituted by a plurality of line images 122. The third mark 110C corresponds to an example of the third position detection mark. The position of the third mark 110C corresponds to an example of the third position detection mark. The position of the third mark 110C is a print position on the print medium M. The data processing unit 35 estimates the position of the third marker 110C from the specified position of the first marker 110A. The data processing unit 35 measures the black density distribution in the third measurement region 130C including the estimated position. The third measurement region 130C is a region having a third measurement region width 130CW and a third measurement region length 130CL as shown in fig. 11. The third measurement region 130C corresponds to an example of the third region. The third measurement region 130C may have the same size as the second measurement region 130B. The third measurement region width 130CW may be the same width as the second measurement region width 130 BW. The third measurement region length 130CL may be the same length as the second measurement region length 130 BL. The third measurement region 130C is narrower than the first measurement region 130A. The position of the third mark 110C is estimated based on the determined position of the first mark 110A, so the estimated position of the third mark 110C is estimated with high accuracy. Even when the third measurement region 130C is narrower than the first measurement region 130A, the data processing unit 35 can specify the position of the third marker 110C. The data processing unit 35 calculates the density centroid of the black density distribution. The data processing unit 35 determines the position of the third marker 110C by calculating the density center of gravity.

As with the third mark 110C, the printing apparatus 10 positions the fourth mark 110D, the fifth mark 110E, the sixth mark 110F, the seventh mark 110G, and the eighth mark 110H.

The printed test pattern image 100 has third marks 110C different from the first marks 110A and the second marks 110B. The printing device 10 specifies the position of the third mark 110C in the third measurement region 130C that is narrower than the first measurement region 130A. Preferably, the printing device 10 positions the third mark 110C in a third measurement area 130C having the same size as the second measurement area 130B.

The printing apparatus 10 can detect the position of the third mark 110C while suppressing the influence of the first pattern 120A adjacent to the third mark 110C.

After the position of the second mark 110B is determined, the printing apparatus 10 determines a defective nozzle in step S109. The data processing unit 35 specifies the position of each line image 122 in the pattern image 120 based on the specified positions of the first mark 110A and the second mark 110B. The data processing unit 35 compares the determined position of each line image 122 with a reference position of each line image 122 estimated in advance. The data processing unit 35 determines a defective nozzle based on a difference between the determined position of each line image 122 and a reference position of each line image 122 estimated in advance. The data processing unit 35 specifies the position of each line image 122 based on the first mark 110A and the second mark 110B. The data processing unit 35 can specify the position of each line image 122 with high accuracy. The printing apparatus 10 can determine not only non-ejection of ink from the ink nozzles 20 but also flight curvature of ink ejected from the ink nozzles 20.

The test pattern image 100 is printed so that the first pattern 120A is arranged at a position adjacent to the first mark 110A, the test pattern image 100 is read, and the read data is acquired, the position of the first mark 110A is specified in the first measurement region 130A, and the position of the second mark 110B is specified in the second measurement region 130B narrower than the first measurement region 130A, and the test pattern image 100 has the pattern images 120 of a plurality of colors including the first mark 110A formed of black, the second mark 110B formed of black, and the first pattern 120A formed of magenta different from black.

The printing apparatus 10 can reduce the influence of the color of the first pattern 120A when determining the position of the first mark 110A. Further, the printing apparatus 10 can reduce the influence of the sixth pattern 120F when the position of the second mark 110B is specified. The printing apparatus 10 can accurately specify the position of the first mark 110A and the position of the second mark 110B.

A printing control program executed by a control unit 30 of a printing apparatus 10 for printing a test pattern image 100 causes the printing control program to print the test pattern image 100 so that a first pattern 120A is arranged at a position adjacent to a first mark 110A, read the test pattern image 100 and acquire read data, specify the position of the first mark 110A in a first measurement region 130A, and specify the position of a second mark 110B in a second measurement region 130B narrower than the first measurement region 130A, the test pattern image 100 having the first mark 110A formed of black, the second mark 110B formed of black, and pattern images 120 of a plurality of colors including the first pattern 120A formed of magenta different from black.

The pattern image 120 is not limited to the stair-stepped pattern shown in fig. 5. The pattern image 120 may be appropriately modified in form as long as it is an image used for evaluation of the printing apparatus 10, such as a patch image for evaluating gradation of colors. In this case, the image adjacent to the marker image 110 may be an image having a color different from that of the marker image 110.

The term "adjacent" in the present specification does not necessarily mean a position as adjacent to each other. Note that the marker image 110 is not necessarily adjacent to the image used for evaluation in the X direction as illustrated in the figure. The marker images 110 are considered to be adjacent to each other as long as they are close to the image used for evaluation to some extent and the detection accuracy of the marker images 110 is degraded due to the positional relationship or the influence of color.

Claims

1. A liquid ejecting apparatus includes:

a printing unit for printing an inspection image;

a reading unit configured to read the inspection image printed by the printing unit; and

an analysis unit for performing analysis based on the reading result read by the reading unit,

the inspection image having a first position detection mark printed with a first color, a second position detection mark printed with the first color, and inspection patterns of a plurality of colors including a second color inspection pattern printed with a second color different from the first color,

the printing section prints the second color check pattern at a position adjacent to the first position detection mark,

the analyzing section determines a first position of the first position detection mark in a first area,

a second position of the second position detection mark is determined in a second area narrower than the first area.

2. The liquid ejection device according to claim 1,

the printing unit performs printing such that the inspection pattern is positioned between the first position detection mark and the second position detection mark with respect to a predetermined direction.

3. The liquid ejection device according to claim 1 or 2,

the analysis section determines the first position from a density distribution of the first color in the first region,

the analysis section determines the second position from a density distribution of the first color in the second region.

4. The liquid ejection device according to any one of claims 1 to 3,

the read result has a first channel extracting a color related to the second color,

the analysis section analyzes the first position detection mark using the first channel.

5. The liquid ejection device according to claim 1,

the inspection image has a third color inspection pattern printed with a third color different from the second color,

the read result has a second channel that extracts a color different from a color associated with the second color,

the analysis section analyzes the second color check pattern using the second channel.

6. An image processing method is characterized in that,

printing an inspection image having a plurality of color inspection patterns including a first position detection mark formed in a first color, a second position detection mark formed in the first color, and a second color inspection pattern formed in a second color different from the first color, in such a manner that the second color inspection pattern is disposed at a position adjacent to the first position detection mark,

the inspection image is read and the read result is acquired,

determining a first position of said first position detection mark in a first area,

the second position of the second position detection mark is determined in a second area narrower than the first area.

7. The image processing method according to claim 6,

the inspection image printed has a third position detection mark different from the first position detection mark and the second position detection mark,

a third position corresponding to the third position detection mark is determined in a third region narrower than the first region.

8. The image processing method according to claim 7,

the second area and the third area are the same size.

9. The image processing method according to any one of claims 6 to 8,

the first position is determined from a density distribution of the first color within the first area,

the second position is determined from a density distribution of the first color within the second region.

10. An image processing program to be executed by a processor of a liquid ejecting apparatus that prints an inspection image,

the image processing program performs the following processing:

printing the inspection image having the first position detection mark formed in a first color, the second position detection mark formed in the first color, and the inspection pattern of a plurality of colors including the second color inspection pattern formed in a second color different from the first color, in such a manner that the second color inspection pattern is arranged at a position adjacent to the first position detection mark,

the inspection image is read and the read result is acquired,